Posted
by
samzenpuson Wednesday May 14, 2014 @12:01PM
from the go-ahead-and-ask dept.

Edward Stone is a professor of physics at the California Institute of Technology who has served as project scientist for the Voyager program from 1972 to the present. Since the launch of the two Voyager spacecraft in 1977, Stone has coordinated the efforts of 11 teams of scientists in their investigations of Jupiter, Saturn, Uranus and Neptune. He served as director of Jet Propulsion Laboratory from 1991 to 2001. Highlights of his career include: Galileo's five-year orbital mission to Jupiter, the launch of Cassini to Saturn, the launch of Mars Global Surveyor and a new generation of Earth science satellites such as TOPEX/Poseidon and SeaWinds, and the successful Mars Pathfinder landing in 1997. Dr. Stone has agreed to sit down with us and answer any questions you may have about his time at JPL and space exploration. As usual, ask as many as you'd like, but please, one question per post.

The guideline was to only ask one question, but the point would be to look forward to the goal of interstellar exploration and envision the types of building block programs that could be started now that could lay the groundwork towards interstellar exploration by robotic probes.

This is what I'd like to see next, an orbiter for each planet. Perhaps orbiters for planets that have not yet had one should be the top space exploration priority. And, launch one for Neptune first because that's the longer trip.
After our own solar system is thoroughly explored, what's next? Giant telescope arrays orbiting the sun as far out or further than the gas giants? An interstellar probe? A close look at Proxima and Alpha Centauri would be fantastic, but getting a working probe there is beyond our

By "shenanigans" I think the poster wants to get you take on the endless delays and defunding of this mission by NASA HQ in Houston so the that money could be used for manned mission pork projects like the Rocket to Nowhere (SLS).

In 2016 the Voyager could become the first interstellar spacecraft. What does this mean to you, and are you hopeful that humans will see for themselves what's out there beyond our solar system space bubble?

As a national leader in robotic exploration of the solar system, what do you think is the role of human spaceflight in the future? Should NASA be developing a human mission to the Moon, Mars, Europa, and beyond? How should the NASA balance the needs of good science and cost/safety issues versus the romance of human exploration?

You often see JPL listed as being a 'NASA Center', but if you look at the JPL website [nasa.gov], it says 'Jet Propulsion Laboratory' followed by 'California Instutite of Technology' (but next to the NASA meatball logo, and in the nasa.gov domain).

I've heard some people joke that if an orbital insertion is successful, then it's "CalTech's JPL" and when something goes wrong, it's "NASA's JPL". Can you explain exactly what the relationship is between the three entities?

During each era of space exploration, going back to the mid-1970's, a manned mission to Mars has been "just 20 years away". At many points over the past 40 years, a variety of factors have converged ensure that a manned Mars mission remained just over the horizon. Even this past month, in NASA Chief Bolden's recent statements, Mars continues to be "just 20 years away", citing a need to stop at an Asteroid on the path to Mars", and budget constraints as reasons that a manned Mars mission remains an unreali

Many groups are talking about manned trip to Mars. Once obstacle is exposure to radiation of all types outside earth's magnetic field.

Setting aside the political/activists issues, how practical would it be to put a reactor on a ship that could generate a magnetic field strong enough to protect the occupants from the forms of radiation expected to be encountered?

If that reactor could be placed on the surface of Mars, would it then be able to offer the same protection to the habitats?

Did you ever want to cooperate more with the Chinese, and if so what stopped you? It's well known that the US blocked Chinese involvement with the ISS, but were there other areas you could have worked with them on?

Why is it that $17 million was spent on a space toilet for the ISS while a Europa mission only gets $15 million (in 2015 and less before that)? Seems to me that NASA's priorities are badly skewed toward manned missions, eh?

Sort of. It was a token amount to try to keep the critics in Congress happy while they keep the gravy train going for the SLS and Orion and ISS and other manned pork. It was like, "See we are actually serious about Planetary Science, we just funded a Europa mission." Of course, they are not serious.
Unfortunately there are two version of NASA. The real science in the Science Directorate (i.e. JPL) and the manned pork. NASA should be split or management should be shook up so that there is equal represe

Do you think NASA could consider/design a Voyager-like mission with a much higher speed, using three-body chaotic gravity assist method, like this article (pdf) [prescientmodels.com] suggests?

Basically, it involves capturing an asteroid in a mutual rotation with the probe, then entering solar gravity assist trajectory with this binary object, then making small adjustments at the right times, so that the probe gets an even bigger kinetic energy boost at the cost of the asteroid losing its energy and falling into the Sun. Maybe there are asteroids or comets with close-to-required orbit where we could take a ride.

To a layman like me, this, while hard, sounds like the most realistic method for reaching speeds relevant for interstellar travel with our current technology. Rosetta spacecraft did perform a successful rendezvous with a comet recently, which looks like a solid stepping stone for a mission like this.

In the early days of the space and aerospace programs it seems a lot of team leaders were engineers who had no college or stopped at a bachelors. Kelly Johnson at the Skunk Works is an example of the later.

When you started out, did you work for any men who didn't have a lot of formal education but were very competent?

We've been thirty years away from putting a man on Mars now for the last forty years. Do you think that by 2035, we'll have finally moved to being just 30 years away from finally putting a man on Mars?

I think your sarcasm is not entirely fair. Several governments and private companies now estimate this at 15-20 years away. It is still not tomorrow, but it is less than 30 years. For instance, SpaceX work on reusable rockets, powered landing and Mars Colonial Transporter looks promising.

If gravity is such a necessary force on our physiology, why haven't we (or maybe, what's the problem with the feasability of) simulated it with centrifugal force? You know, like having structures rotating at a sufficient velocity in space to test out if the illusion of the gravity is sufficient?

Since generating artificial gravity is science fiction, simulated gravity with centrifugal force seems testable. Wouldn't knowing this help solve a big part of the problem with long-term space habitation and construc

Because centrifugal force isn't trivial. You need a big radius to revolve in to avoid tide-like problems, it's stress on components, and it can be hard to observe things from a rotating platform. There may be other problems, but these are the ones that come to mind.

Every time I hear about people wanting to have a manned trip to Mars, I have to roll my eyes. It seems that we are just nowhere near what is needed to actually perform one, namely a long term space habitat probably needing spin gravity, minimal leakage, and propulsion, especially assuming that such things would need to be tested and the actual Mars shot would be far down the mission scale (comparable how Apollo 11 was the one that made it to the surface of the moon). Talk of a one way trip sound even sillier to me as I figure once we have the ability to actually confidently get to Mars, getting back would be fairly trivial. My question is that if we, the USA or the world, how far do you think we are away from being able to send a manned mission to Mars in terms of time, money, and technology? Second, would that manned mission be cheaper than doing the same work with robotic missions?

My question is that if we, the USA or the world, had the political will to do so, how far do you think we are away from being able to send a manned mission to Mars in terms of time, money, and technology? Second, would that manned mission be cheaper than doing the same work with robotic missions?

To expand on this for general conversation. Looking at orbital physics, it seems that a Mars mission will take about two years. 7-9 months to get to Mars, a stay of several months then another 7-9 months back at the optimal times in the Earth-Mars orbits. Leaving at other times or attempting quicker transit speeds greatly increases the distances or fuel needed as to be prohibitive. Therefore, we'll need a long term space habitat for the astronauts. How many we'll need is a questions but I would guess that t

Considering the possible existence of other civilizations, could we equip our interstellar starship with "radar" able to track objects wrapping spacextime or generating supraluminal signatures, as a source of intelligent life out there?!?!? was not found on this server.

The Planetary Grand Tour [wikipedia.org] was reduced from 4 to 2 probes but those Voyagers are great space exploration success.

Such planetary configuration will occur again in quite a long time, about 130 years, however we must be able by then to launch a new set of probes to take advantage of the gravitational slingshots [wikipedia.org]. I'm afraid humanity might not be able to achieve this in case of new economic crisis at that time or because of some world conflicts, society collapse, whatever may distract us (or impede us) from workin